Cognitive Activity in Insomnia

Type

View/Open

Date

Author

Share

Metadata

Abstract

The study investigated the causal relationship between worry and insomnia. A 2 x 2 design (Worry x Induced sleeplessness) with repeated measures was employed. In all 96 female undergraduate students who scored high or low on a measure of worry (Penn State Worry Questionnaire) completed the study. The induced sleeplessness variable consisted of two levels defined by a double-blind distribution of 300 mg caffeine and placebo. The repeated measures were nocturnal cognitive activity, as measured by the Night-Time Thoughts Questionnaire, and sleep parameters derived from a sleep diary and an actigraph. The data were obtained from two consecutive nights. Worry was found to be associated with nocturnal cognitive activity on both nights and with subjective sleep parameters on the first night. The findings indicate that nocturnal cognitive activity occurs as an epiphenomenon of wakefulness. The results are discussed in terms of their relationship to various categories of cognitive activity and models of insomnia. A core implication of the findings is that cognitive activity caused by induced sleeplessness may be conceived of as rumination. There is a need for the development of an instrument that can distinguish between types of nighttime rumination, under which worry is one subgroup.